10 - higher fitness than homozygous 3 This pattern...

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Lecture 4: Evolutionary Processes : 1/11/10 A. Hardy-Weinberg Principle 1) Acts as a null hypothesis when researchers want to test whether evolution or nonrandom mating is affecting a particular gene 2) Predicts what genotype frequencies will be when evolutionary mechanisms are not affecting the gene 3) Four evolutionary mechanisms exist: 4) Only natural selection produces adaption 5) Genetic drift causes random fluctuations in allele frequencies 6) Gene flow equalizes allele frequencies between population 7) And mutation introduces new alleles B. Patterns of Natural Selection 1) Natural selection occurs in a side variety of patterns 2) Ex: Heterozygote advantage is a pattern of natural selection in which heterozygous individuals have
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Unformatted text preview: higher fitness than homozygous. 3) This pattern maintains genetic variation in a population C. Directional Selection 1) A pattern of natural selection that is a pattern of natural selection that increases the frequency of one allele. D. Stabilizing Selection 1) Occurs when individuals with intermediate traits reproduce more than others 2) As a result, intermediate phenotypes are maintained in a population Discussion 1/15/10 Evolutionary Mechanisms 1) Mutation 2) Genetic Drift--> Little/no selection pressure 3) Gene flow 4) Natural selection 1. Disruptive selection 2. Directional 3. Stabilizing-- genes are favored to approach mean 5) Random mating...
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This note was uploaded on 11/19/2010 for the course BIOLOGY 93 taught by Professor O during the Spring '08 term at San Diego.

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